Whack them down your drains with hot water to clean it out. Can put them in the bottom of pans with some water, will lift burnt on grease right off. I wet my bathroom suite, shake some on, rub around with a cloth, leave for an hour then rinse of and rub with a cloth.You can put them in with greyed white washing and they'll come up lovely, amazing on school/work shirts. Cheaper than vanish power too.Cleans ovens amazingly.

They can be dangerous though. Make sure you check the packet and there will be a list of things you shouldn't use them on and why.

If you google soda crystals it'll take you to the company that sells the bags and they have loads of suggestions for using them. I like soaking Tupperware tubs in a solution when they're stained/holding on to food smells etc.